Bone loss after acute sex-hormone removal via gonadectomy prior to skeletal maturity most striking in male but not female animals

Menopause, an age-related loss of sex hormone production in women, is one of the most common causes of osteoporosis. Previous work has established that this loss of sex hormones, in particular estrogen, causes dramatic loss of bone volume and strength. Similarly, removal of sex steroids results in acute loss of bone mass in adult animals. Mouse models of sex steroid-deficiency include surgery removing the sex organs (orchidectomy, ORX, for males; ovariectomy, OVX, for females) are commonly used to understand the role of sex steroids in bone, but are typically preformed at animal maturity (16 weeks of age) and are analyzed six weeks post-operation. This study aimed to determine whether acute removal of the male or female sex hormones prior to maturity would impact the cortical and trabecular bone volume. Gonadectomy or sham operations were performed on mice at 11 weeks of age, and femurs were then harvested either 2 weeks (13 weeks of age) or 4 weeks postsurgery (15 weeks of age). Analysis of the cortical and cancellous bone volume of the femur were assessed by microCT. In cancellous bone, male animals two and four weeks ORX demonstrated decreases in the following parameters compared to sham operated, agematched controls (2 week; 4 week): bone volume (BV/TV, -70.9%; -86.6%), tissue mineral density (V-TMD, -8.69%; -17.9%), trabecular thickness (TbTh, -31.9%; -27.8%), and trabecular number (TbN, -57.5%; -81.4%). In cancellous bone, female animals two and four weeks OVX demonstrated decreases in the following parameters compared to sham operated, agematched controls: BV/TV (-61.2%; -41.0%), V-TMD (-30.7%; -15.6%), and TbN (-64.0%; -42.4%). In cortical bone, male animals four weeks ORX demonstrated decreases in the following parameters compared to sham operated, age-matched controls: cortical area (-13.8%), Endocortical bone surface (-7.10%), and TMD (-10.2%). In cortical bone, female animals four weeks OVX demonstrated decreases in only TMD (-7.50%) compared to sham operated, age-matched controls. In summary, the acute removal of sex hormones has a larger impact on cancellous bone in both males and females, with male animals showing increasing bone loss as time progressed. Further studies are needed to understand the underlying mechanisms behind the progressive bone loss seen in males after sex hormone depletion.

Creator

• Momeni, Nick
• Deosthale, Padmini
• Essex, Alyson
• Plotkin, Lilian

Language

• English

Parola chiave

• acute sex-hormone removal
• Menopause
• Osteoporosis
• Animals
• gonadectomy

Date created

• 2021

Related URL

• Audio presentation:  https://marian.hosted.panopto.com/Panopto/Pages/Viewer.aspx?id=82299818-74b9-42d3-bc68-adf70123117c

Resource type

• Poster

Rights statement

• http://rightsstatements.org/vocab/InC/1.0/